1. Technical Field
Example embodiments of the present invention relate to a video communication apparatus, and more particularly, to a video communication apparatus having an eye-to-eye communication function that enables video communication users to communicate with each other in an eye-to-eye state, and a method thereof.
2. Related Art
Recently, communication between users is being shifted from telephone and conferencing using only voice to telephone and conferencing using video.
In video communication, eye-to-eye contact between video communication partners shows which position a partner holds in a conversation and to what degree the partner is interested in the other partner's speech, and is a very important element in video communication. The eye-to-eye contact provides a clue as to when a conversation has begun or when someone has begun speaking to adjust the flow of a conversation. The eye-to-eye contact is a part of non-verbal language indicating that one partner is interested in conversation with the other partner. Further, emotional states are known to be observable through motions of the eyes, forehead, mouth, and facial muscles that play an important role in conveying emotion.
However, since a camera for video communication in most currently commercially available video communication apparatuses is installed in an upper portion of a display device, it is difficult to hold a conversation in eye-to-eye contact with a video communication partner, which degrades a sense of reality. In particular, the larger the display device is, the more severe the problem.
In video communication, techniques for eye-to-eye contact between callers include hardware-based approaches and software-based approaches.
The hardware-based approaches include optical division schemes, such as a half-transparent mirror (UM) scheme or a blazed half-mirror (BEM) scheme, space division schemes, and time division schemes.
In the half-transparent mirror scheme, a figure of a user viewing a screen is reflected by a half-transparent mirror and input to a camera. The half-transparent mirror must be tilted 45° before a monitor. Accordingly, a distance between a user and the monitor increases in proportion to a size of the monitor, increasing an overall system size. Further, in the half-transparent mirror scheme, the half-transparent mirror passes only half of an amount of light and reflects the other half. Accordingly, the screen viewed by the user is not clear and a separate mechanism for camera installation is necessary.
In the BHM scheme, several small-sized half-transparent mirrors are disposed in parallel with a monitor and a camera is disposed orthogonal to an angle of reflection of a BHM. The BHM scheme has resolved a problem of an increasing distance between the half-transparent mirror and the monitor in the half-transparent mirror scheme. However, in the BHM scheme, a specially made half-transparent mirror is necessary and there is still a restriction on a camera installation space.
In the space division scheme, a small hole is formed in a position of a screen in which a partner's eyes are displayed, a small camera is installed in the hole, and an image of the partner is projected onto the screen using a video projector. This scheme has drawbacks in that the hole is formed in the screen and the camera hole is shown to be superimposed on the image of the partner. Further, since strong light of the video projector is directly input to the camera, light rays incident from the projector and incident light rays reflected from a user are discriminated using, for example, a polarizing filter.
In the time division scheme, a camera and a video projector are placed behind a switchable LCD panel, in which, when a LCD is driven, an image of a partner is displayed, and when the LCD is not driven, an image of a user is captured by a camera through a transparent LCD. In this scheme, the camera or a display can use half of a total time, such that intensity of light rays incident to the camera and an amount of displayed light are disadvantageously reduced.
Further, since the conventional methods provide similar effects to eye-to-eye contact with a certain limitation on a distance between the camera and a person, a size of the display device, etc., the eye-to-eye contact between callers is often not practically achieved. For example, if a photographed person is too large or small, it is difficult to obtain the eye-to-eye contact effect when the person is not located in a center. The larger the device is, the more sever this problem is.
Additionally, a software-based method includes a method of correcting a line of sight by subjecting a captured video to three-dimensional processing. However, in this method, a video of a person must be corrected in real time and output. Thus, it is practically difficult to output a corrected video without delay, and a delay time increases as a size of a display screen increases.